已知A=x3-5x2,B=x2-11x+6,求A-2B的值.

问题描述:

已知A=x3-5x2,B=x2-11x+6,求A-2B的值.

∵A=x3-5x2,B=x2-11x+6,
∴A-2B=(x3-5x2)-2(x2-11x+6)
=x3-5x2-2x2+22x-12
=x3-7x2+22x-12.